The present invention relates to a brake adjusting device for bicycles.
When the desired braking force lowers due to the wear of brake shoes or the elongation of bowden cable, there arises the necessity to properly adjust the clearance between the rim of the wheel and the working surface of the brake shoe by advancing an adjusting screw member provided at one end of the bowden cable connected to the brake or at the other end thereof connected to the brake operating member to enable the inner element of the bowden cable to exert a greater pulling force or to increase the pushing force of the other element of the cable. However, since the adjustment described above is effected manually by rule of thumb, it is extremely difficult to advance the adjusting screw by such an amount as to give an optimum brake clearance which is usually about 2 mm. Not infrequently, therefore, the adjusted clearance is greater or smaller than the proper value, entailing further difficulties in ensuring safety performance. More specifically, if the clearance is larger than the proper value, a delayed braking action will result. Conversely a smaller clearance gives rise to an abrupt braking action and leads to a falling accident. The conventional adjusting means therefore involves serious problems in securing safety.